This study focuses on how GDP growth in developed and developing European countries is affected by the use of renewable energy from 2000 to 2023, taking into consideration factors including FDI, labor participation, trade openness, and capital formation. Using panel data analysis, the research employs pooled OLS, fixed effects, and random effects models, with the Hausman test favoring fixed effects. An interaction term accounts for differences in development levels. The findings reveal a negative effect of renewable energy on growth in developing countries, while capital formation and trade openness have positive effects. Labor participation and FDI are not consistently significant. The study highlights the need for developing countries to enhance infrastructure and institutions to manage renewable transitions. It offers valuable comparative insights across development stages.